The present invention is directed to humanized antibodies specific for human gp39, DNA encoding such antibodies, methods for their production, pharmaceutical compositions containing, and the use of such humanized antibodies as therapeutic agents. These antibodies have particular application in the treatment of autoimmune diseases including, e.g., rheumatoid arthritis, multiple sclerosis, diabetes, and systemic lupus erythematosus as well as non-autoimmune diseases including, e.g., graft-versus-host disease and for preventing graft rejection.
The immune system is capable of producing two types of antigen-specific responses to foreign antigens. Cell-mediated immunity is the term used to refer to effector functions of the immune system mediated by T lymphocytes. Humoral immunity is the term used to refer to production of antigen-specific antibodies by B lymphocytes. It has long been appreciated that the development of humoral immunity against most antigens requires not only antibody-producing B lymphocytes but also the involvement of helper T (hereinafter Th) lymphocytes. (Mitchison, Eur. J. Immunol., 1:18-25 (1971); Claman and Chaperon, Transplant Rev., 1:92-119 (1969); Katz et al, Proc. Natl. Acad. Sci. USA, 70:2624-2629 (1973); Reff et al, Nature, 226:1257-1260 (1970)). Certain signals, or xe2x80x9chelpxe2x80x9d, are provided by Th cells in response to stimulation by Thymus-dependent (hereinafter TD) antigens. While some B lymphocyte help is mediated by soluble molecules released by Th cells (for instance lymphokines such as IL-4 and IL-5), activation of B cells also requires a contact-dependent interaction between B cells and Th cells. (Hirohata et al, J. Immunol., 140:3736-3744 (1988); Bartlett et al, J. Immunol., 143:1745-1765 (1989)). This indicates that B cell activation involves an obligatory interaction between cell surface molecules on B cells and Th cells. Such an interaction is further supported by the observation that isolated plasma membranes of activated T cells can provide helper functions necessary for B cell activation. (Brian, Proc. Natl. Acad. Sci. USA, 85:564-568 (1988); Hodgkin et al, J. Immunol., 145:2025-2034 (1990); Noelle et al, J. Immunol., 146:1118-1124 (1991)).
It is further known that in a contact-dependent process termed xe2x80x9cT cell helper functionxe2x80x9d, CD4+ T lymphocytes direct the activation and differentiation of B lymphocytes and thereby regulate the humoral immune response by modulating the specificity, secretion and isotype-encoded functions of antibody molecules (Mitchell et al, J. Exp. Med., 128:821 (1968); Mitchison, Eur. J. Immunol., 1:68 (1971); White et al, J. Exp. Med., 14:664 (1978); Reinherz et al, Proc. Natl. Acad. Sci. USA, 74:4061 (1979); Janeway et al, Immunol. Rev., 101:39 (1988); O""BRIEN et al, J. Immunol., 141:3335 (1988); Rahemtulla et al, Nature, 353:180 (1991); and Grusby et al, Science, 253:1417 (1991)).
The process by which T cells help B cells to differentiate has been divided into two distinct phases; the inductive and effector phases (Vitetta et al, Adv. Immunol., 45:1 (1989); Noelle et al, Immunol. Today, 11:361 (1990)). In the inductive phase, resting T cells contact antigen-primed B cells and this association allows clonotypic T cell receptor (TCR)-CD4 complexes to interact with Ia/Ag complexes on B cells (Janeway et al, Immunol. Rev., 101:39 (1988); Katz et al, Proc. Natl. Acad. Sci., 70:2624 (1973); Zinkernagel, Adv. Exp. Med., 66:527 (1976); Sprent, J. Exp. Med., 147:1159 (1978); Sprent, Immunol. Rev., 42:158 (1978); Jones et al, Nature, 292:547 (1981); Julius et al, Eur. J. Immunol., 18:375 (1982); Chestnut et al, J. Immunol., 126:1575 (1981); and Rogozinski et al, J. Immunol., 126:735 (1984)). TCR/CD4 recognition of Ia/Ag results in the formation of stable T-B cognate pairs and bi-directional T and B cell activation (Sanders et al, J. Immunol., 137:2395 (1986); Snow et al, J. Immunol., 130:614 (1983); Krusemeier et al, J. Immunol., 140:367 (1988); Noelle et al, J. Immunol., 143:1807 (1989); Bartlett et al, J. Immunol., 143:1745 (1989); and Kupfer et al, Annu. Rev. Immunol., 7:309 (1987)). In the effector phase, activated T cells drive B cell differentiation by secreting lymphokines (Thompson et al, J. Immunol., 134:369 (1985)) and by contact-dependent stimuli (Noelle et al, J. Immunol., 143:1807 (1989); Clement et al, J. Immunol., 140:3736 (1984); Crow et al, J. Exp. Med., 164:1760 (1986); Brian, Proc. Natl. Acad. Sci., USA, 85:564 (1988); Hirohata et al, J. Immunol. 140:3736 (1988); Jover et al, Clin. Immunol. Immun., 53:90 (1989); Whalen et al, J. Immunol., 141:2230 (1988); Pollok et al, J. Immunol., 146:1633 (1991); and Bartlett et al, J. Immunol., 143:1745 (1990)), both of which are required for T cells to drive small resting B cells to terminally differentiate into Ig secreting cells (Clement et al, J. Immunol., 132:740 (1984); Martinez et al, Nature, 290:60 (1981); and Andersson et al, Proc. Natl. Acad. Sci., USA, 77:1612 (1980)).
Although the inductive phase of T cell help is Ag-dependent and MHC-restricted (Janeway et al, Immun. Rev., 101:34 (1988); Katz et al, Proc. Natl. Acad. Sci., USA, 10:2624 (1973); Zinkernagle, Adv. Exp. Med. Biol., 66:527 (1976)); the effector phase of T cell helper function can be Ag-independent and MHC-nonrestricted (Clement et al, J. Immunol., 132:740 (1984); Hirohata et al, J. Immunol., 140:3736 (1988); Whalen et al, J. Immunol., 143:1715 (1988)). An additional contrasting feature is that the inductive phase of T cell help often requires CD4 molecules and is inhibited by anti-CD4 mAb (Rogozinski et al, J. Immunol., 126:735 (1984)), whereas helper effector function does not require CD4 molecules (Friedman et al, Cell Immunol., 103:105 (1986)) and is not inhibited by anti-CD4 mAbs (Brian, Proc. Natl. Acad. Sci., USA, 85:564 (1988); Hirohata et al, J. Immunol., 140:3736 (1988); Whalen et al, J. Immunol., 143:1745 (1988); and Tohma et al, J. Immunol., 146:2547 (1991)). The non-specific helper effector function is believed to be focused on specific B cell targets by the localized nature of the T-B cell interactions with antigen specific, cognate pairs (Bartlett et al, J. Immunol., 143:1745 (1989); Kupfer et al, J. Exp. Med., 165:1565 (1987) and Poo et al, Nature, 332:378 (1988)).
Although terminal B cell differentiation requires both contact- and lymphokine-mediated stimuli from T cells, intermediate stages of B cell differentiation can be induced by activated T cell surfaces in the absence of secreted factors (Crow et al, J. Exp. Med., 164:1760 (1986); Brian, Proc. Natl. Acad. Sci., USA, 85:564 (1988); Sekita et al, Eur. J. Immunol., 18:1405 (1988); Hodgkin et al, J. Immunol., 145:2025 (1990); Noelle et al, FASEB J, 5:2770 (1991)). These intermediate effects on B cells include induction of surface CD23 expression (Crow et al, Cell Immunol., 121:94 (1989)), enzymes associated with cell cycle progression (Pollok et al, i J. Immunol., 146:1633 (1991)) and responsiveness to lymphokines (Noelle et al, FASEB J, 5:2770 (1989); Pollok et al, J. Immunol., 146:1633 (1991)). Recently some of the activation-induced T cell surface molecules that direct B cell activation have been identified. Additionally, functional studies have characterized some features of activation-induced T cell surface molecules that direct B cell activation. First, T cells acquire the ability to stimulate B cells 4-8 h following activation (Bartlett et al, J. Immunol., 145:3956 (1990) and Tohma et al, J. Immunol., 146:2544 (1991)). Second, the B cell stimulatory activity associated with the surfaces of activated T cells is preserved on paraformaldehyde fixed cells (Noelle et al, J. Immunol., 143:1807 (1989); Cros et al, J. Exp. Med., 164:1760 (1986); Pollok et al, J. Immunol., 146:1633 (1991); Tohma et al, J. Immunol., 146:2544 (1991); and Kubota et al, Immunol., 72:40 (1991)) and on purified membrane fragments (Hodgkin et al, J. Immunol., 145:2025 (1990) and Martinez et al, Nature, 290:60 (1981)). Third, the B cell stimulatory activity is sensitive to protease treatment (Noelle et al, J. Immunol., 143:1807 (1989); Sekita et al, Eur. J. Immunol., 18:1405 (1988); and Hodgkin et al, J. Immunol., 145:2025 (1990). Fourth, the process of acquiring these surface active structures following T cell activation is inhibited by cycloheximide (Tohma et al, J. Immunol., 196:2349 (1991) and Hodgkin et al, J. Immunol., 195:2025 (1990)).
A cell surface molecule, CD40, has been identified on immature and mature B lymphocytes which, when crosslinked by antibodies, induces B cell proliferation. Valle et al, Eur. J. Immunol., 19:1463-1467 (1989); Gordon et al, J. Immunol., 140:1425-1430 (1988); Gruder et al, J. Immunol., 142:4144-4152 (1989).
CD40 has been molecularly cloned and characterized (Stamenkovic et al, EMBO J., 8:1403-1410 (1989)).
CD40 is expressed on B cells, interdigitating dendritic cells, macrophages, follicular dendritic cells, and thymic epithelium (Clark, Tissue Antigens 36:33 (1990); Alderson et al, J. Exp. Med., 178:669 (1993); Galy et al, J. Immunol. 142:772 (1992)). Human CD40 is a type I membrane protein of 50 Da and belongs to the nerve growth factor receptor family (Hollenbaugh et al, Immunol. Rev., 138:23 (1994)). Signaling through CD40 in the presence of IL-10 induces IgA, IgM and IgG production, indicating that isotype switching is regulated through these interactions. The interaction between CD40 and its ligand results in a primed state of the B cell, rendering it receptive to subsequent signals.
Also, a ligand for CD40, gp39 (also called CD40 ligand or CD40L) has recently been molecularly cloned and characterized (Armitage et al, Nature, 357:80-82 (1992); Lederman et al, J. Exp. Med., 175:1091-1101 (1992); Hollenbaugh et al, EMBO J., 11:4313-4319 (1992)). The gp39 protein is expressed on activated, but not resting, CD4+ Th cells. Spriggs et al, J. Exp. Med., 176:1543-1550 (1992); Lane et al, Eur. J. Immunol., 22:2573-2578 (1992); and Roy et al, J. Immunol., 151:1-14 (1993). Cells transfected with gp39 gene and expressing the gp39 protein on their surface can trigger B cell proliferation and, together with other stimulatory signals, can induce antibody production. Armitage et al, Nature, 357:80-82 (1992); and Hollenbaugh et al, EMBO J., 11:4313-4319 (1992). In particular, the ligand for CD40, gp39, has been identified for the mouse (Noelle et al, Proc. Natl. Acad. Sci. USA, 89:6550 (1992); Armitage et al, Nature, 357:80 (1992)) and for humans (Hollenbaugh et al, Embo. J. 11:4313 (1992); Spriggs et al, J. Exp. Met., 176:1543 (1992)). gp39 is a type II membrane protein and is part of a new gene super family which includes TNF-xcex1, TNF-xcex2 and the ligands for FAS, CD27, CD30 and 4-1BB.
Expression of gp39 can be readily induced in vitro on CD4+ T cells using either anti-CD3 antibody or phorbol myristate acetate (PMA) plus ionomycin. Expression is rapid and transient, peaking at 6-8 hours and returning to near resting levels between 24 and 48 hours (Roy et al, J. Immunol., 151:2497 (1993)). In vivo, gp39 has been reported in humans to be present on CD4+T cells in the mantle and centrocytic zones of lymphoid follicles and the periarteriolar lymphocyte sheath of the spleen, in association with CD40+ B cells (Lederman et al, i J. Immunol., 149:3807 (1992)). gp39+ T cells produce IL-2, IL-4 and IFN-xcex3 (Van der Eetwegh et al, J. Exp. Med., 178:1555 (1993)).
Unique insights into the novel role of gp39 in the regulation of humoral immunity have been provided by studies of a human disease, X-linked hyper-IgM syndrome (HIM). HIM is a profound, X-linked immunodeficiency typified by a loss in thymus dependent humoral immunity, the inability to produce IgG, IgA and IgE. Mutations in the gp39 gene were responsible for the expression of a non-functional gp39 protein and the inability of the helper T cells from HIM patients to activate B cells (Allen et al, Science, 259:990 (1993); Aruffo et al, Cell, 72:291 (1993); DiSanto et al, Nature, 361:541 (1993); Korthauer et al, Nature, 361:539 (1993)). These studies support the conclusion that early after T cell receptor engagement of the peptide/MHC class II complex, gp39 is induced on the cognate helper T cell, and the binding of gp39 to CD40 on the B cell induces the B cell to move into the cell cycle and differentiate to immunoglobulin (Ig) secretion and isotype switching.
Functional studies have shown that treatment of mice with anti-gp39 completely abolished the antibody response against thymus dependent antigens (SRBC and TNP-KLH), but not thymus independent antigens (TNP-Ficoll) (Foy et al, J. Exp. Med., 178:1567 (1993)). In addition, treatment with anti-gp39 prevented the development of collagen-induced arthritis (CIA) in mice injected with collagen (Durie et al, Science, 261:1328 (1993)). Finally, anti-gp39 prevented formation of memory B cells and germinal centers in mouse spleen (Foy et al, J. Exp. Med., 180:157 (1994)). Collectively, these data provide extensive evidence that the interaction between gp39 on T cells and CD40 on B cells is essential for antibody responses against thymus dependent antigens.
Recently, a number of murine models of autoimmune disease have been exploited to evaluate the potential therapeutic value of anti-gp39 administration on the development of disease. A brief discussion of the results of studies in these models are provided below:
Collagen-Induced Arthritis
CIA is an animal model for the human autoimmune disease rheumatoid arthritis (RA) (Trenthorn et al, J. Exp. Med., 146:857 (1977)). This disease can be induced in many species by the administration of heterologous type II collagen (Courtenay et al, Nature, 283:665 (1980); Cathcart et al, Lab. Invest., 54:26 (1986)).
To study the effect anti-gp39 on the induction of CIA (Durie et al, Science, 261:1328 (1993)) male DBA1/J mice were injected intradermally with chick type II collagen emulsified in complete Freund""s adjuvant at the base of the tail. A subsequent challenge was carried out 21 days later. Mice were then treated with the relevant control antibody or anti-gp39. Groups of mice treated with anti-gp39 showed no titers of anti-collagen antibodies compared to immunized, untreated control mice. Histological analysis indicated that mice treated with anti-gp39 antibody showed no signs of inflammation or any of the typical pathohistological manifestations of the disease observed in immunized animals. These results indicated that gp39-CD40 interactions are absolutely essential in the induction of CIA. If the initial cognate interaction between the T cell and B cell is not obtained, then the downstream processes, such as autoantibody formation and the resulting inflammatory responses, do not occur.
Recently it has been shown that gp39 is important in activating monocytes to produce TNF-xcex1 and IL-6 in the absence of GM-CSF, IL-3 and IFN-xcex3 (Alderson et al, J. Exp. Med., 178:669 (1993)). TNF-xcex1 has been implicated in the CIA disease process (Thorbecke et al, Eur. J. Immunol., 89:7375 (1992) and in RA (DiGiovane et al, Ann. Rheum. Dis., 47:68 (1988); Chu et al, Arthrit. Rheum., 39:1125 (1991); Brennan et al, Eur. J. Immunol., 22:1907 (1992). Thus, inhibition of TNF-xcex1 by anti-gp39 may have profound anti-inflammatory effects in the joints of arthritic mice. Both inhibition of TNF-xcex1 and of T cell-B cell interactions by anti-gp39 may be contributory to manifestations of CIA.
Experimental Allergic Encephalomyelitis (EAE)
EAE is an experimental autoimmune disease of the central nervous system (CNS) (Zamvil et al, Ann. Rev. Immunol., 8:579 (1990) and is a disease model for the human autoimmune condition, multiple sclerosis (MS) (Alvord et al, xe2x80x9cExperimental Allergic Model for Multiple Sclerosis,xe2x80x9d NY 511 (1984)). It is readily induced in mammalian species by immunizations of myelin basic protein purified from the CNS or an encephalitogenic proteolipid (PLP). SJL/J mice are a susceptible strain of mice (H-2s) and, upon induction of EAE, these mice develop an acute paralytic disease and an acute cellular infiltrate is identifiable within the CNS.
Classen and co-workers (unpublished data) have studied the effects of anti-gp39 on the induction of EAE in SJL/J mice. They found that EAE development was completely suppressed in the anti-gp39 treated animals. In addition, anti-PLP antibody responses were delayed and reduced compared to those obtained for control animals.
EAE is an example of a cell-mediated autoimmune disease mediated via T cells, with no direct evidence for the requirement for autoantibodies in disease progression. Interference with the interaction between gp39 and CD40 prevents disease induction and the adoptive transfer of disease.
Chronic (c) and Acute (a) Graft-versus-host-disease (GVHD)
Chronic and acute GVHD result from donor cells responding to host disparate MHC alleles. In cGVHD (H-2d-- greater than H-2bd), heightened polyclonal immunoglobulin production is due to the interaction of allospecific helper T cells and the host B cells. In vivo administration of anti-gp39 antibody blocked cGVHD-induced serum anti-DNA autoantibodies, IgE production, spontaneous immunoglobulin production in vitro, associated splenomegaly and the ability to transfer disease. Durie F. H. et al, J. Clin. Invest., 94:133 (1994). Antibody production remained inhibited for extended periods of time after termination of anti-gp39 administration. Anti-allogeneic cytotoxic T lymphocyte (CTL) responses induced in GVHD were also prevented by the in vivo administration of anti-gp39. These data suggest that CD40-gp39 interactions are critical in the generation of both forms of GVHD. The fact that CTL responses were inhibited and a brief treatment with anti-gp39 resulted in long-term prevention of disease suggest permanent alterations in the T cell compartment by the co-administration of allogeneic cells and anti-gp39 antibody.
Various research groups have reported the production of murine antibodies specific to gp39, which are disclosed to possess therapeutic utility as immunosuppressants. For example, WO 93/09812, published May 27, 1993, and assigned to Columbia University; EP 0,555,880, published Aug. 18, 1993, and PCT US/94/09872, filed Sep. 2, 1994 by Noelle et al and assigned to Dartmouth College, describe murine antibodies specific to gp39 and their use as therapeutics and immunosuppressants.
Also, Scaria et al, Gene Therapy, 4:611-617 (1997) report the use of an antibody to gp39 to inhibit humoral and cellular immune responses to a DNA (adenoviral/vector).
However, while murine antibodies have applicability as therapeutic agents in humans, they are disadvantageous in some respects. Specifically, murine antibodies, because of the fact that they are of foreign species origin, may be immunogenic in humans. This often results in a neutralizing antibody response, which is particularly problematic if the antibodies are desired to be administered repeatedly, e.g., in treatment of a chronic or recurrent disease condition. Also, because they contain murine constant domains they may not exhibit human effector functions.
In an effort to eliminate or reduce such problems, chimeric antibodies have been disclosed. Chimeric antibodies contain portions of two different antibodies, typically of two different species. Generally, such antibodies contain human constant and another species, typically murine variable regions. For example, some mouse/human chimeric antibodies have been reported which exhibit binding characteristics of the parental mouse antibody, and effector functions associated with the human constant region. See, e.g., Cabilly et al, U.S. Pat. No. 4,816,567; Shoemaker et al., U.S. Pat. No. 4,978,745; Beavers et al., U.S. Pat. No. 4,975,369; and Boss et al., U.S. Pat. No. 4,816,397, all of which are incorporated by reference herein. Generally, these chimeric antibodies are constructed by preparing a genomic gene library from DNA extracted from pre-existing murine hybridomas (Nishimura et al, Cancer Research, 47:999 (1987)). The library is then screened for variable region genes from both heavy and light chains exhibiting the correct antibody fragment rearrangement patterns. Alternatively, cDNA libraries are prepared from RNA extracted from the hybridomas and screened, or the variable regions are obtained by polymerase chain reaction. The cloned variable region genes are then ligated into an expression vector containing cloned cassettes of the appropriate heavy or light chain human constant region gene. The chimeric genes are then expressed in a cell line of choice, usually a murine myeloma line. Such chimeric antibodies have been used in human therapy.
In a commonly assigned application, Ser. No. 07/912,292, xe2x80x9cPrimatizedxe2x80x9d(trademark) antibodies are disclosed which contain human constant and Old World monkey variable regions. These Primatized(trademark) antibodies are well tolerated in humans given their low or weak immunogenicity.
Also, humanized antibodies are known in the art. Ideally, xe2x80x9chumanizationxe2x80x9d results in an antibody that is less immunogenic, with complete retention of the antigen-binding properties of the original molecule. In order to retain all the antigen-binding properties of the original antibody, the structure of its combining-site has to be faithfully reproduced in the xe2x80x9chumanizedxe2x80x9d version. This can potentially be achieved by transplanting the combining site of the nonhuman antibody onto a human framework, either (a) by grafting the entire nonhuman variable domains onto human constant regions to generate a chimeric antibody (Morrison et al, Proc. Natl. Acad. Sci., USA, 81:6801 (1984); Morrison and Oi, Adv. Immunol., 44:65 (1988) (which preserves the ligand-binding properties, but which also retains the immunogenicity of the nonhuman variable domains); (b) by grafting only the nonhuman CDRs onto human framework and constant regions with or without retention of critical framework residues (Jones et al, Nature, 321:522 (1986); Verhoeyen et al, Science, 239:1539 (1988)); or (c) by transplanting the entire nonhuman variable domains (to preserve ligand-binding properties) but also xe2x80x9ccloakingxe2x80x9d them with a human-like surface through judicious replacement of exposed residues (to reduce antigenicity) (Padlan, Molec. Immunol., 28:489 (1991)).
Essentially, humanization by CDR grafting involves transplanting only the CDRs onto human fragment onto human framework and constant regions. Theoretically, this should substantially eliminate immunogenicity (except if allotypic or idiotypic differences exist). However, it has been reported that some framework residues of the original antibody also need to be preserved (Riechmann et al, Nature, 332:323 (1988); Queen et al, Proc. Natl. Acad. Sci. USA, 86:10,029 (1989)).
The framework residues which need to be preserved can be identified by computer modeling. Alternatively, critical framework residues may potentially be identified by comparing known antibody combining site structures (Padlan, Molec. Immun., 31(3):169-217 (1994)).
The residues which potentially affect antigen binding fall into several groups. The first group comprises residues that are contiguous with the combining site surface which could therefore make direct contact with antigens. They include the amino-terminal residues and those adjacent to the CDRs. The second group includes residues that could alter the structure or relative alignment of the CDRs either by contacting the CDRs or the opposite chains. The third group comprises amino acids with buried side chains that could influence the structural integrity of the variable domains. The residues in these groups are usually found in the same positions (Padlan, 1994 (Id.) according to the adopted numbering system (see Kabat et al, xe2x80x9cSequences of proteins of immunological interest, 5th ed., Pub. No. 91-3242, U.S. Dept. Health and Human Services, NIH, Bethesda, Md., 1991).
However, while humanized antibodies are desirable because of their potential low immunogenicity in humans, their production is unpredictable. For example, sequence modification of antibodies may result in substantial or even total loss of antigen binding function, or loss of binding specificity. Alternatively, xe2x80x9chumanized antibodiesxe2x80x9d may still exhibit immunogenicity in humans, irrespective of sequence modification.
Thus, there still exists a significant need in the art for novel humanized antibodies to desired antigens. More specifically, there exists a need in the art for humanized antibodies specific to gp39, because of their potential as immunotherapeutic agents.
Toward this end, it is an object of the invention to provide humanized antibodies which are specific to human gp39.
More specifically, it is an object of the invention to provide humanized antibodies derived from murine antibodies to gp39 and in particular 24-31, a specific murine antibody which binds to human gp39.
It is also an object of the invention to provide pharmaceutical compositions containing humanized antibodies which are specific to human gp39.
It is a more specific object of the invention to provide pharmaceutical compositions containing humanized antibodies derived from 24-31, a murine antibody which specifically binds to human gp39.
It is another specific object of the invention to provide methods of using humanized antibodies to human gp39 for treatment of human disease conditions, which are treatable by modulation of gp39 expression and/or inhibition of the gp39/CD40 binding interaction including, e.g., autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, multiple sclerosis, idiopathic thrombocytopenic purpura (ITP), diabetes and non-autoimmune conditions such as graft-versus-host disease and transplantation.
It is still another object of the invention to provide nucleic acid sequences which encode for humanized antibodies to human gp39.
It is a more specific object of the invention to provide nucleic acid sequences which encode humanized antibodies derived from 24-31, a murine antibody which specifically binds to human gp39 antigen.
It is another object of the invention to provide vectors which provide for the expression of humanized antibodies to human gp39, in particular humanized antibodies derived from 24-31, a murine antibody which specifically binds to human gp39 antigen.
In its broadest embodiment, the present invention is directed to humanized antibodies which retain not less than about one-tenth and more preferably not lower than one-third the gp39 antigen binding affinity of the murine 24-31 antibody and/or which retain not less than about one-tenth and more preferably not less than about one-third the in vitro functional activity of the murine antibody 24-31, e.g., in B-cell assays which measure T-cell dependent antibody production. More particularly, the present humanized antibodies retain at least one-tenth and more preferably at least about one-third the half-maximal potency in in vitro functional activity in a B cell assay at a concentration of not more than three times the concentration of the 24-31 antibody.
The present invention is further directed to humanized antibodies which bind to the same epitope as the murine 24-31 antibody and/or which are capable of competing with the murine 24-31 antibody for inhibiting the binding of CD40 to gp39 and/or which contain the CDR""s of the 24-31 antibody.
The present invention is more preferably directed to humanized antibodies derived from murine 24-31 which possess the humanized variable light sequences and/or humanized variable heavy sequences [SEQ ID NOS: 1-4] set forth below:
(1) DIVMTQSPSFLSASVGDRVTITC KASQNVITAVA WYQQKPGKSPKLLIY SASNRYT GVPDRFSGSGSGTDFTLTISSLQPEDFADYFC QQYNSYPYT FGGGTKLEIK;
(2) DIVMTQSPDSLAVSLGERATINC KASQNVITAVA WYQQKPGQSPKLLIY SASNRYT GVPDRFSGSGSGTDFTLTISSLQAEDVADYFC QQYNSYPYT FGGGTKLEIK;
(3) DIVMTQSPSFMSTSVGDRVTITC KASQNVITAVA WYQQKPGKSPKLLIY SASNRYT GVPDRFSGSGSGTDFTLTISSMQPEDFADYFC QQYNSYPYT FGGGTKLEIK;
(4) DIVMTQSPDSMATSLGERVTINC KASQNVITAVA WYQQKPGQSPKLLIY SASNRYT GVPDRFSGSGSGTDFTLTISSMQAEDVADYFC QQYNSYPYT FGGGTKLEIK
and a humanized variable heavy sequence [SEQ ID NOS: 5-8] selected from the following group:
(1) EVQLQESGPGLVKPSETLSLTCTVSGDSIT NGFWI WIRKPPGNKLEYMG YISYSGSTYYNPSLKS RISISRDTSKNQFSLKLSSVTAADTGVYYCAC RSYGRTPYYFDF WGQGTTLTVSS;
(2) EVQLQESGPGLVKPSQTLSLTCTVSGDSIT NGFWI WIRKHPGNKLEYMG YISYSGSTYYNPSLKS RISISRDTSKNQFSLKLSSVTAADTGVYYCAC RSYGRTPYYFDF WGQGTTLTVSS;
(3) EVQLQESGPGLVKPSQTLSLTCAVSGDSIT NGFWI WIRKHPGNKLEYMG YISYSGSTYYNPSLKS RISISRDTSNNQFSLNLNSVTRADTGVYYCAC RSYGRTPYYFDF WGQGTTLTVSS;
(4) EVQLQESGPGLVKPSETLSLTCAVYGDSIT NGFWI WIRKPPGNKLEYMG YISYSGSTYYNPSLKS RISISRDTSKNQFYLKLSSVTAADTGVYYCAC RSYGRTPYYFDF WGQGTTLTVSS
as well as variants and equivalents thereof. Variants and equivalents thereof in the present invention are intended to embrace humanized immunoglobulin sequences wherein one or several of the amino acid residues in the above identified humanized variable heavy and/or variable light sequences are modified by substitution, addition and/or deletion in such manner that does not substantially effect gp39 antigen binding affinity. In particular, the present invention embraces variants and equivalents which contain conservative substitution mutations, i.e., the substitution of one or more amino acids by similar amino acids. For example, conservative substitution refers to the substitution of an amino acid within the same general class, e.g., an acidic amino acid, or a basic amino acid, a neutral amino acid by another amino acid within the same class. What is intended by a conservative amino acid substitution is well known in the art. Preferably, such variants and equivalents will retain not less than about one-tenth and more preferably not less than about one-third the gp39 antigen binding affinity as the parent murine 24-31 antibody and more preferably not less than about one-third the gp39 antigen binding affinity as the murine 24-31 antibody. Additionally, such variants and equivalents will preferably retain not lower than one-tenth and more preferably retain at least about one-third the in vitro functional activity of murine antibody 24-31, e.g., in B-cell assays which measure T-cell dependent antibody production. More preferably, these variants and equivalents will retain at least about one-third the in vitro functional activity of murine antibody 24-31, for example, in B-cell assays which measure T-cell dependent antibody production. More specifically, these antibodies will retain the half-maximal potency in in vitro functional activity in a B cell assay at a concentration of not more than about three times the concentration of the parent 24-31 antibody.
The present invention is further directed to nucleic acid sequences which encode for the expression of such humanized antibodies, as well as expression vectors which provide for the production of humanized antibodies in recombinant host cells. In the most preferred embodiments these DNA sequences will encode for the humanized variable heavy and/or humanized variable light sequences [SEQ ID NOS:1-4] set forth below:
(1) DIVMTQSPSFLSASVGDRVTITC KASQNVITAVA WYQQKPGKSPKLLIY SASNRYT GVPDRFSGSGSGTDFTLTISSLQPEDFADYFC QQYNSYPYT FGGGTKLEIK;
(2) DIVMTQSPDSLAVSLGERATINC KASQNVITAVA WYQQKPGQSPKLLIY SASNRYT GVPDRFSGSGSGTDFTLTISSLQAEDVADYFC QQYNSYPYT FGGGTKLEIK;
(3) DIVMTQSPSFMSTSVGDRVTITC KASQNVITAVA WYQQKPGKSPKLLIY SASNRYT GVPDRFSGSGSGTDFTLTISSMQPEDFADYFC QQYNSYPYT FGGGTKLEIK;
(4) DIVMTQSPDSMATSLGERVTINC KASQNVITAVA WYQQKPGQSPKLLIY SASNRYT GVPDRFSGSGSGTDFTLTISSMQAEDVADYFC QQYNSYPYT FGGGTKLEIK
and a humanized variable heavy sequence [SEQ ID NOS: 5-8] selected from the following group:
(1) EVQLQESGPGLVKPSETLSLTCTVSGDSIT NGFWI WIRKPPGNKLEYMG YISYSGSTYYNPSLKS RISISRDTSKNQFSLKLSSVTAADTGVYYCAC RSYGRTPYYFDF WGQGTTLTVSS;
(2) EVQLQESGPGLVKPSQTLSLTCTVSGDSIT NGFWI WIRKHPGNKLEYMG YISYSGSTYYNPSLKS RISISRDTSKNQFSLKLSSVTAADTGVYYCAC RSYGRTPYYFDF WGQGTTLTVSS;
(3) EVQLQESGPGLVKPSQTLSLTCAVSGDSIT NGFWI WIRKHPGNKLEYMG YISYSGSTYYNPSLKS RISISRDTSNNQFSLNLNSVTRADTGVYYCAC RSYGRTPYYFDF WGQGTTLTVSS;
(4) EVQLQESGPGLVKPSETLSLTCAVYGDSIT NGFWI WIRKPPGNKLEYMG YISYSGSTYYNPSLKS RISISRDTSKNQFYLKLSSVTAADTGVYYCAC RSYGRTPYYFDF WGQGTTLTVSS.
Moreover, the present invention also embraces equivalent and variants thereof as defined supra.
The present invention is further directed to the use of the above-identified humanized antibodies specific to gp39 as pharmaceuticals. The present invention is also directed to the use of the subject humanized anti-gp39 antibodies for treating diseases treatable by modulation of gp39 expression or by inhibition of the gp39/CD40 interaction. The present invention is more particularly directed to the use of humanized antibodies of the above-identified humanized antibodies specific to gp39 for the treatment of autoimmune disorders, for example, rheumatoid arthritis, multiple sclerosis, diabetes, systemic lupus erythematosus and ITP. The present invention is further directed to the use of the subject humanized antibodies to gp39 for the treatment of non-autoimmune disorders including graft-versus-host disease and for inhibiting graft rejection.
Also, the subject invention is further directed to usage of the subject humanized antibodies as immunosuppressants, in particular during gene or cellular therapy. The subject humanized antibodies should enhance the efficacy of gene therapy or cellular therapy by inhibiting adverse immunogenic reaction to vectors and cells used therein. For example, they may be used to inhibit humoral and cellular immune responses against viral vectors, e.g., retroviral vectors, adenoviral vectors. Also, the use of such antibodies should enable such cells or vectors to be administered repeatedly, which will facilitate treatment of chronic diseases such as cancers and autoimmune diseases.